Expanding friction clutch for motor cars



June 24, 1930. w. H. MCBRIDE 1,767,387 `Iszxwnmmcf FRIcTIoN CLUTCH Fonuo'roR CARS Filed April e, 192s 2 sheets-sheet 1 Invcn for June 24,1930. w. H. MCBRIDE EXPANDING FRICTION CLUTCH FIOR KOTOR CARS FiledApril 6, 1928 2 Sheetksheet 2 Patented June Y24, `193i.)`

UNITEDgSTATES WILLIAM HILL 'IvIcB'RIDn orfcontrBRIDGE,y SCOTLAND ,Y i

ExrANDINe, FfaIo'rIon `CLUiio1Iro1tMoToa CARS@Y I This invention relatesto an' improved expanding friction clutch for motor cars :and thelike.The invention has for itsobject to provide a clutch of improvedy andsimplified construction which as will `be hereinafter seen is admirablysuited'to cope with traffic, and with crowded thoroughfares. It engageseasily without jump, or jolt, whilst the least movement of the clutchpedal will discng'age the friction segments. Vith this clutch starting,or stopping, or gliding jalong slowly in the wake of traiic becomes amatter of easy manipulation. y

In construction it is a simple clutch, and the replacing vof anypartiseasily effected. By carrying spare partsfwhichmight be required-such asbalance springs Vand ten sile vsprings-#clutch trouble may* be put 0right onthe road ina shorttime, instead of becoming a garageY jobA of.days` duration. My improved expanding friction clutch consists of two?segments, feathered and fitted into slotson `a driving disc -tofwhichthe segments" are attachedfby four yguide Y bolts, the feathers of thesegments being so fitted andthe nuts of the guidebolts so adjustedA thatthe friction flanges of `the segments expandeasily to thefriction ringon the flywheel.: The two segments are simultaneouslyexpanded by the useof four bell-crank levers, two balance springs and two tensile spiralsprings. Each of the segments is provided with a seating or` bearingagainst which the balance springs work, and atoggle bracket fixedrigidly in position. `The segments are contracted by means of togglesworking in the toggle bracketson the' segments having their fulcra inlugs ,on the' hub ofthe driving disc, the expanding arms of the togglelevers `being attached by four links-two Von, eachside-to a slidingsleeve with an expanding spiral springy on the driven shaft between thedriving dischub and the sliding sleeve. Y p

In order that my said invention maybe clearly understood it ishereinafter described ings in which to connect with with reference tothe accompanying draw- Figure `691s a section4 on theline 6-6iof y`Figure 5; Figure j 7 bracket;

` Figure 8 `is 8--8- of Fig. 7;' l i Figure 9 is a longitudinal sectionlof a toggle bracket; i

`is an elevation of a toggle a section` taken on the line Figure 10 is aside view of one of twov balance springs for expanding the segments;Figure 11 is a plan ofsaid'balance spring joints to bell-crank top/andbottom arms; .v Y lFigures' 12, 13v and Figures 14,15 showW two `sets ofbell-,cranks forconnecting said expanding segments to said springs; t

Figure `16` shows a turned studfwhich is fitted into the driving disc tocarryl the bellcranks v sile spiralhsprings to the side -arms of thekbell-crank levers i Figure 18 shows a turned;n guide -pin for fixingthe `expanding segmentstothe driv ing disc; i

` Figure 19 showsvatoggle lever to fitrinto existing flywheel itI willbe necessaryto' have y lso Figure 17 shows a pinfor fixing the tenafriction ring a rigidly fixed on the rim of the flywheel. In the casewhere a new flywheel is made to take the driving disc b, this can bedone with very little alteration of the pattern.

In Figure 2 of the accompanying drawings there is shown a friction ring,a, rigidly iXed on an existing flywheel, andalso my improved drivingdisc, b, fully mounted in position with a ball-thrust bearing 20 betweenthe flywheel and the driving 'dis'c' to take up the tlirustfromtheflywheel.; The..

driving disc is to be made as shown in Figures and,y i oftheaccompanying draw.- ings, with four holes 21 for guide-bolts ofsegments, fourholes 22. for stud pinsV to carry the. bell-crankstwoslots `23 to take the feathers of thev segments, and.v withl a hub 24cast in( thecentre having 'lugs 25 to take the toggle levers.

Mounted. on the vdrivingdisc are tivo segments c lined on their rimswith the material knoivn under. 'the registered Crade-.mark name FeroddThesesegments are to b e fitted on 'the discv in such-Wise that thefeathers 26 of the segments ,fitneatly into the'V slots of the, disc,and work easily. The segments are to be held to the disc by fourguide-pins 'i which are fitted into the disc and pass through oblongslots 27 in the segments. The nuts ofvtheguide b0l,tsare V to be soadjusted as to allow thesegments to slide freely upon .the face .ofthedisk, A lug 28 is cast on the inner sideof the friction flange of eachsegment and restsonthe. balance. springe. which connects the top andbottom armsofthe.bell-cranks f, which are fulcrumed at their anglesonthe disc., the segments having notches 29 intheir chorda'l edges toclearthe'fulcrum pins.. Qrbolts, and the bell 'cranks lying inplanesparallel Withtheplaneofthe segments.

The other arms of the bell-.cranks -are coupled together by thetensilespiralsprings m, thus combining all the expandingA elements intoone'great unit Whichgives an equal pressure all overthe frictionsurfaceof the clutch.A Vhen the car. isY running centrifugal'force. comes inand controlsthe whole expanding arrangements of the clutch. Theexpansion of the segments is operatec from the 'tensile spiral springsYm whichv connect the side arms of the bell-cranks. The pull of saidvsprings on the side arms of the bell cranks rocks the bellecrank.levers so that the balance springs c ai'e tightened against the lugs 28ofthe segments andthe segments are caused to frictionally engage thering a on the flywheel. y

It is to be noted that the balance springs e are to be made from veryflexible spring steel so that theycan lend rthemselves readily to thedeflection of the lugs 28 and the tension Vof the belllcrankarms.

To connect the tensile spiral springs m to the bell-crank side arms fourlink pins 7i are used. These link pins are each'tiirned with a shoulderl30, and have a collar or nut 31 at the end to prevent the eye of thespring from slipping off. There is one of said link .pins fitted. intoeach. of. the side arms of the. bell-cranks attheexti'eme ends.TheNbell-cranks themselves are fitted to the driving disc by turnedstuds g, and work freely in the slots or notches 29 at the bases ofAthe, segments. y'lonrvetract the segments and vso ldisengage thev clutchthe following device .is used. There are twovanglerd levers j, havingforged ends which are'fitted into the toggle brackets d, on thesegments. The centresk ofthese two angled levers are fitted into thelugs 25 on the hub of thediiving disc and theirM outer arms areconnected to thelngs 3201i the slidingsleeveAZby,l links,

la. Onthejdrivenlshaft betweenthe hub of the driving disc ,and thesliding sleeve. there `is an expanding spiral spring n, which bringsback theclutcli pedal to normal positionrwhen the-foot pressure lhasbeen released. Just below the head ofthe sliding sleeve there is agroove turned to fitA the swivel pads of a forked wiper in a well knownmaniier. i: y* v Y WhatfI claimisgl. Av friction clutch comprising 'an'outer ring, a rotatable .disc, segments slidably meiintediipontheface-ofthe disc iii-posi,- tion to engage the. inner surfa, Of the ring,

angle: levers fulcrunied upon the disc and;

arranged'in pairs, olne', pair being disposed adjacent .eachl segment,"evener springs extending between the levers,offeachpair and engaging.the respective segments `whereby t0i held.' themen fifitonel..engagement with the ring, and tensile springs connecting the pas www.. rv

2. A friltioii clutch.coniprising .an outer ring,I a rotatable diskarrz'ingedl concentric with the.y ring, segments slidably mounted on.

thev face ollffthe. disc and providedcwithwinveidlrpreiecteglugsfbetveen their" enfle, angley `levers fu.lcrumed upon the disc y andarrangedin pairs, one pair being disposed toy cooperate with eacllllr'segment., evenei' springs leXtending between and carried 'by theleyersfofach pair' and bearing upQIl the res'. pvectiveA lugs onl the 'segmeiits,` and tensile springs connecting 'the VVpairs of levers. I A Yln testimony whereofl haveV hereunto signed my name.

WILLIAM HILL MGBRiDn

